package com.fhz.day005.test

/**
 * 时间:2021/10/19
 * @author msfeng
 * 简述: TODO
 */
interface Subject {
    //增加用户
    fun attach(observer: Observer)

    //删除用户
    fun detach(observer: Observer)

    //消息通知
    fun notify(string: String)
}